Cette citation est attribuée à Marguerite Yourcenar, extraite de son œuvre 'Mémoires d'Hadrien' (1951), un roman historique sous forme de lettre autobiographique fictive de l'empereur romain Hadrien.
"Friendship is indispensable to man for the proper functioning of his memory. To remember one's past, to always carry it with oneself, is perhaps the necessary condition for preserving, as they say, the integrity of one's self."